1. Technical Field
This invention relates to an aqueous coating composition such as coatings, inks, coverprint varnish and surface treatment applications containing an oxazoline or oxazine acetoacetate polymer.
2. Background Art
In the following description of the prior art and in the Examples, the parenthetical numbers are described in the following Reference section. Acetoacetamide, acetoacetanilide, and acetoacetate functionalized chemicals are readily available, via reaction of amines or hydroxyl substituted molecules with diketene (1-3), alkyl acetoacetates, or the readily used acetoacetalation compound 2,2,6-trimethyl-1,3-dioxin-4-one, which is prepared from reaction of diketene with acetone (2,4). Organic compounds or polymers with the acetoacetamide, acetoacetanilide, or acetoacetate type functionality are known to react with a variety of other functional chemicals (1-5), including such things as amines, aldehydes, and isocyanates, giving various adducts in excellent yields at low reaction temperatures (2). Also, the acetoacetamide, acetoacetanilide, or acetoacetate group, with amine catalysts, will combine readily with the acrylate functionality, via what is commonly called the Michael addition reaction (2,5,6). Further, these acetoacetanilide, acetoacetamide, or acetoacetate groups are known to readily react with various metal compounds, such as CaO, Ca(OH).sub.2, BaO, CoCI.sub.2, NiCI.sub.2, etc. to form metal complexes (1,3), where the chemistry has been used to prepare polymeric catalysts (2,7,8) and crosslinked coatings (6,9-11). These chemicals with the acetoacetamide, acetoacetanilide, and/or acetoacetate functionality, which have three active centers, have found extensive utility in the formation of metal-complexes, manufacture of dyes and synthesis of heterocycles (1-3).
It is well known that cyclic imino ethers, such as oxazolines and oxazines will undergo cationic, ring-opening polymerizations (12) and zwitterionic copolymerization with such things as acrylic acid, maleimides, anhydrides, lactones, etc. (13-17). It is also well known that molecules with the oxazoline or oxazine residues will undergo ring-opening reactions with compounds such as carboxylic acids, thiols (HS-groups), phenols, alkyl halides, etc., giving 1-to-1 adducts (18-24), allowing for step-growth copolymerizations to be readily achieved with difunctional monomers. Further, it has been shown that alkyl halides will initiate ring-opening polymerization of cyclic imino ethers, as well as give 1:1 adducts (18, 25). Thus oxazolines and oxazines are excellent intermediates for synthesis of variety of polymeric materials, both thermoplastics and thermosets, by chain-growth and step-growth polymerization mechanisms or combinations thereof. In addition, the synthesis and polymerization of oxazoline and oxazine methacrylate aqueous coating compositions are also known (27).